Tag: Blower Fan Canada

Industrial Fans & Noise

The important factor to consider is the fan’s blade pass frequency, which is a pure tone produced when the blades of the fan wheel (impeller) rotate past the housing cut-off sheet in centrifugal fans, or the turning vanes, in axial fans. The blade pass frequency is calculated by multiplying the number of blades times the rotating speed in revolutions per minute. If this frequency matches the natural frequency of the ductwork, it can excite the ductwork, which can cause it to resonate, thereby increasing the noise level. Because of this possible increase in sound, and because certain pure tones are irritating to people, the sound output of the blade pass frequency should be investigated when sound reduction is desired. The next factor to consider is the fan design. Generally a fan operating at peak mechanical efficiency will produce less noise, because high efficiencies result from minimal air turbulence within the fan.

The sound generated by some fans can be a potential hazard to personnel in close proximity to the fan, and the sound can be transmitted, via the ductwork connected to the fan, to all areas serviced by the fan. Because of these concerns, fan manufacturers publish sound ratings for their products to serve as a guide for selecting fans to meet sound specifications, and to assist acoustical consultants in predicting the total noise levels in specific environments. This article provides basic information to help understand fan sound ratings and how to apply them. Like any mechanical device, fans generate sound, which emanates naturally from the turbulence of moving air, the mechanics of moving parts of the fan, and from vibration.

Air turbulence within the fan increases the sound coming from the air movement. The noise resulting from air turbulence is a major factor in the sound levels of a fan in a specific application. Further, duct work can transmit this turbulent noise to all areas serviced by the fan. Factors contributing to air turbulence include the resistance to flow, flow separation along fan surfaces, and shock related to abrupt changes in the direction of airflow, pressure, or velocity. A lower noise level can be achieved by reducing air turbulence. This can be done by considering several factors related to air movement when selecting fans.

Industrial Centrifugal Fans Design

There are four basic centrifugal fan wheel designs – forward curved, backwardly inclined, radial, and radial tip – and a variety of axial flow wheel designs. Each wheel design has unique sound characteristics due to the way they handle air, and the efficiencies they can achieve. Fan speed does not always determine which fan will be quieter. For example, centrifugal fans have higher amplitudes at lower frequencies, while axial fans exhibit higher amplitudes at the higher frequencies. The amplitude of the blade pass frequency on an axial fan is higher and more pronounced than on backwardly-inclined fans, and commonly will have amplitude peaks at multiples of this frequency.

Backward Inclined Fans

Of the four centrifugal designs, the backwardly inclined fans are the most efficient, and therefore, the quietest. Those with airfoil-shaped blades offer the highest efficiencies, for clean air environments, while those with single-thickness blades can be used in applications where light dust or moisture is present, although the efficiencies are somewhat lower.

Axial & Vaneaxial Industrial Fans

Certain types of axial fans offer the next highest efficiencies. An excellent example is the Vaneaxial fan that uses airfoil shaped blades in an in-line flow design. This fan is used to handle high volumes of clean air at low pressures, which is a typical ventilation application.

Radial Blade Fans

Radial fans are typically low efficiency, open designs for special purpose applications, such as bulk material handling, or exhausting / supplying lower volumes of air at higher pressures. A radial fan will be much louder than a backwardly-inclined fan operating under the same volume and pressure conditions.

Radial Tip Fans

Radial Tip fans, commonly used to handle larger volumes of air that contains particles or material, exhibit sound characteristics similar to the radial fans. The sound spectra of radial and radial tip fans contain amplitude spikes at various frequencies, and a noticeable spike at the blade pass frequency.

Forward Curve Fans

The forward-curved fan design operates at speeds that are much slower than the other fan types, which results in lower noise levels from mechanical operation and vibration. However, because of its modest efficiencies, a forward curved fan may be noisier than a backwardly-inclined fan when operating at comparable volume and pressure. The sound spectrum of the forward-curved fan shows a slower rate of reduction in amplitudes than the other centrifugal types, and because of the large number of blades, the blade pass frequency occurs much later in the spectrum and is not predominant.

Industrial Fan Components

The moving components of the fan – the motor, bearings, and drive – produce sound. This too can be transmitted through the system via the fan structure or shaft, or when these components are in the airstream. Motor sound will vary with speed, enclosure, electrical characteristics, and even the manufacturer. Antifriction bearings can be used to reduce bearing noise, and proper drive selection will reduce the likelihood of belt hop, or slap. Of course, proper maintenance must be employed to keep the moving parts running smoothly, and quietly.

Excessive vibration can significantly add to the overall noise level of an installation. This will occur if the fan or any of its components are not adequately balanced, if the fan is installed on an insufficient foundation, or if the fan is not properly isolated from other system components. For example, it is not uncommon for the fan’s support structure or ductwork to have a natural frequency at the fan’s operating speed or blade pass frequency, either of which can cause the system to resonate at that frequency, increasing the sound levels, and the possibility of damaging the installation. These risks can be eliminated by changing the speed of the fan, installing appropriate isolation, and / or detuning of the fan or affected system components.

dBA is a useful measurement for evaluating the overall noise level at a particular location, but this measurement takes into account all of the sound sources affecting that particular location, which include the sounds from all equipment in the area, natural sounds of the environment, and from other environmental factors. Some of these factors are the current physical properties of the air such as temperature, humidity, and pressure, whether the location is outside or inside, the size and material of the room. All of these affect the sound pressure experienced by the listener, and recorded by the sound level meter.

Published fan sound power ratings and corrections only reflect noise created by air turbulence within the fan. Because of the infinite variables, mechanical noise and vibration noise are impossible to accurately predict, and are not included in the rating.

Additional information can be found at the Northern Fan web site http://northernindustrialsupplycompany.com/products/ventilators.html

Industrial Fans Canada

People these days opt to use fans for their ventilation needs. A mechanical fan often has many uses around the house and inside buildings. This versatile appliance can serve as a cooling instrument especially during the summer and it can also be used during winter to push warm air down in order to heat a room.

Axial fans, centrifugal fans

In the industry, there are many types of fans such as axial fans, centrifugal fans, crossflow fans and bladeless fans. These types of fans have features, structures and benefits. Each one offers different processes and ways of balancing the temperature. Their usage also depends on the kind and size of the room that needs ventilation. This enables engineers to choose the right kind of ventilation that will coincide with the design they have in mind for their buildings.

Axial Fans

Axial fans are the typical household fans we see every day. This type of fan has three or more blades that rotate to allow air to pass through and circulate around a room. Axial fans are operated by electricity to balance the temperature and permit air to flow inside a room.

Damper Fan

A damper fan is a duct-like device used to neutralize temperature through ventilation ducts. There are many damper manufacturers who produce fire dampers that help prevent the spreading fires in buildings and houses. These fans are designed to close once subjected to heat and/or fire. Engineers and architects are incorporating fire dampers in their design to effectively reduce the damage that a fire can cause.

A dampers manufacturer makes sure that its products are safe for use by consumers. They make certain that their products materials are of the highest grade and quality so as not to risk the safety of the building where the fans will be used.

Centrifugal Fan

A centrifugal fan manufacturer sells fans that are quite different from the other types of fans. This type of fan is composed of different instruments which control the fans speed. It is a typically larger mechanism compared to other fans to accommodate bigger structures like office buildings and factories. All of these fans aim to maintain the convenience of the people regarding temperature balance.

Industrial Ventilators – High Temperature

One of the most critical components of the fan are the bearings. So naturally if the bearings are kept out of the hot airstream they are less susceptible to the effects of the high temperature, and therefore the air temperature can be higher than the limiting temperature of the bearings. Inline fans inherently have drive components in the airstream. In such cases, the unit can sometimes be designed so that cooler outside air is drawn over the drive components, providing some additional cooling. Incorporating this type of external cooling is one of the main reasons Northern Fan medium pressure tube axial inline fan (TBI) can be used for high temperature exhaust applications. There are, however, some arrangements that donÕt allow for the incorporation and benefits of external cooling. For instance, fans in arrangement 3 have the wheel suspended in-between the two bearings. Consequently, one or both of the bearings will always be located in the air stream. Similarly, direct drive fans are limited by the maximum operating temperature of the motor, since the motor is located directly in the hot air stream. That is why most often high temperature exhaust fans are required to be belt driven units; typically the motor is the temperature-limiting component of the unit when it is installed in the airstream. Other than the installation location of the bearing within the fan assembly, other critical points to consider include the type of lubrication in the bearing, as well as the construction of the bearing itself. There is a seemingly endless list of lubricants available for most any application, but the appropriate lubricant can add considerable life to bearing operation. In addition, high temperature bearings can be constructed with inherent construction modifications, such as a larger grease cavity to hold more lubricant.

Industrial Fan Design

Another common variation to the standard fan design is the addition of insulation. The bearing mounting plate, bearing cover and belt tube are the most likely components to be insulated for a high temperature application. Northern Fan automatically includes insulation for these components on all fans specified with either HT Option III or HT Option IV.

Exhaust Fans

It is important to understand that emergency smoke exhaust fans are designed to operate effectively for the temperature and time limits stated as long as the power supply to the fan is not terminated. Since they are not designed to sustain higher temperatures for continuous use, exposure to the extreme high temperatures caused by a fire likely would destroy some or all parts of the fan once the time design limit has elapsed, rendering it incapable of future operation.

High Temperature Fans

Fans that are built for continuous high temperature ventilation have many of the same construction features and options as those built for emergency smoke exhaust. For example, both are typically constructed of higher temperature ferrous materials, have high temperature bearings, have the motor and drive installed either out of the airstream or with some type of additional cooling capabilities, and incorporate some heat shielding or insulation. There are, however, some distinct differences between the fan designs for the two application categories. One of the most common applications for which continuous duty high temperature exhaust fans are specified is commercial kitchen ventilation.

Fans that are specified for continuous operation at higher temperatures need to be carefully selected taking into account air density corrections. Although a fan will move the same amount of air at two different temperatures, the static pressure and horsepower requirements can change drastically as the density of the air varies with changing temperatures. For example, if a fan moves 3,000 CFM at 70 F it will also move 3,000 cfm at 500 F. However, since the hotter air weighs much less than the 70 F air, the fan will require less brake horsepower and will create less static pressure.

There are also some accessories and construction options that are incorporated into high temperature process fans to increase the limiting temperature. For example, a heat slinger can be installed on the shaft between the fan housing and the inboard bearing. A heat slinger is an aluminum disc that absorbs and dissipates some of the heat conducted along the shaft before it travels to the bearings. Many heat slingers incorporate fans that promote additional inboard bearing cooling because it circulates air with every rotation of the shaft.

Another common construction technique is the use of a heat gap. A heat gap is a physical gap between the bearing support structure and the hot fan housing. This separation slows the process of heat conduction to the bearings and drive components through the housing and support structure. An expansion bearing should be installed where the fan shaft is predicted to conduct enough heat that it could expand to a length greater than that of the structure to which it is secured. This allows for expansion of the shaft within the bearing due to the higher temperatures.

High temperature applications can be found in many different areas of the air movement and control industry. It is important to remember that one high temperature fan design is not suited to all applications.

Additional information can be found at the Northern Fan web site http://www.northernindustrialsupplycompany.com/products/heat_exchangers.html

Industrial Fan Performance

Visual inspections of the ventilation system often reveal some easily rectified problems that can significantly impair performance. If the system has not been properly maintained, clogged filters or obstructed coils will reduce airflow. The greater the obstruction, the greater the loss in airflow. Any leaks in the ductwork will contribute to reduced performance, especially leaks around plenum bulkheads that can lead to recirculation of air. Worn flexible connectors are a common source of leaks and should be inspected regularly. If the damper linkage is out of adjustment, the damper may not be opening completely, thereby reducing performance. If inlet dampers are used, make sure they are installed so that the air is pre-spun in the same direction as wheel rotation. For all dampers, make sure there is sufficient clearance for the blades to open and close completely without hitting the ductwork or other system components. Last, for systems with either pneumatic or electric controls, make sure damper actuators are operating properly. Sharp changes in the direction of airflow at either the fan inlet or outlet will disrupt the flow through the fan and impair performance. If it is impossible to straighten the ductwork entering and leaving the fan, the use of inlet boxes and turning vanes can minimize performance losses.

Industrial processes and plant ventilation

Industrial processes and plant ventilation systems often need more air than originally designed. Increased production requirements, process changes, and facility renovations are a few of the major reasons. Additionally, the lack of adequate maintenance over time can negatively impact system airflows. This article discusses several procedures that can increase airflow. Often airflow can be increased by adhering to proper fan maintenance procedures as outlined in fan installation and maintenance literature.

Centrifugal Fans & Fan Speed

Fan speed can decrease by as much as 10% to 20% when belts are too loose, with a corresponding loss of airflow. A fan cannot perform as designed if the air flow surfaces are distorted by contaminants. Even in large fans, a sixteenth of an inch of build up can reduce performance. Centrifugal fans will move some air even when running backwards. While some types would use so much horsepower they would trip circuit breakers, other design s could run for years without being detected. Fan components may be out of position due to routine cleaning or painting or the wheel could have shifted during shipment. For backward inclined fans, the relation of wheel to inlet cone is very critical. Even a quarter of an inch can have a major impact. The fan’s installation and maintenance literature shows the proper positioning of the wheel to the inlet cone.

Low Airflow Problems

One of the easiest solutions to low airflow problems is speeding up the fan. While airflow is increased by speeding up the fan, so too are static pressure, noise, and power requirements. Therefore, while increasing the fan’s speed is an easy procedure with low first cost, the additional operating expense over time makes it the most costly solution. When increasing fan speed, it is necessary to check the maximum safe speed of the fan and make sure the motor is capable of the horsepower required to run the fan at the new speed. But never run a fan beyond its maximum safe speed.

Industrial Fans & Improving Airflow

On a first-cost basis, adding or replacing fan equipment is the most costly alternative. However, on a life-cycle-cost basis, considering operating and maintenance expense, it can be the least expensive, as compared to increasing the speed of an existing fan. Sometimes a second fan may be added, either in series or parallel with the original, although it may be more cost effective to simply upgrade the system with a new fan capable of the required airflow and pressure. Adding another fan in series will increase the airflow because of the additional pressure. The operating point of the new system moves further out/up the system curve. Where duct size is adequate to handle the desired amount of air but the existing fan doesn’t provide sufficient pressure, a second fan in series may be the best solution. However, make sure the ductwork can handle the increase in pressure. Adding another fan in parallel with the first will increase airflow due to the combined capacities. Because capacities are being combined instead of pressures, a greater increase in airflow will result for a given system. However, system pressures will also increase and caution is required to avoid the unstable operating area of the combined fan system.

When more air is required it is important to investigate the system on a step-by-step basis, considering the least expensive possibilities first. For existing systems that seem to have lost performance, fan and system maintenance is the place to start. Often, simply improving the efficiency of existing components will suffice. For systems that require greater airflow and / or pressure, increased fan speed is generally the first alternative. However, when large increases in performance are required, there may be no alternative but to purchase a larger fan.

Industrial Fans – Types

Different models of fans are available in the market in various unique designs, integrated with the latest technologies and low power consumption facilities. The variety of elegant fans includes integrated gear box and push button switch to suit any decor.Many stylish fans with double ball bearing are available in lots of colors which are integrated with dynamically balanced blade for maximum air delivery.The use of radial blower in the fans helps in moving air perpendicular to the blower axis and provides relatively low flow rates and high pressures.

Types of Blowers & Fans

The wide range of blowers and fans includes non-decorative Ceiling fans, wall mount fans, decorative ceiling fans, single centrifugal blowers, dual centrifugal blowers, radial wheel blowers, cast aluminum blowers, high pressure blowers, belt driven blowers, explosion proof and food safe blowers, high temperature oven circulating fans, industrial fans and also stainless steel and other alloy fans are available in the market. Finest quality, durability and enduring performances of these fans are catching more attention of the market these days. A wide range of axial flow fans is designed to provide efficient trouble free service & reduce the initial and operating cost to minimum. Apart from the fans there are various other products like air blowers, air scrubbers, axial fans, axial flow fans, centrifugal blowers, cyclone seperators, dust collecting equipment, dust collector, exhaust blowers, fan blowers, industrial blowers and many more.

Non-Decorative Ceiling Fans are integrated with the low power consumption facility with double ball bearing for maximum air delivery and available at very reasonable price. Non-Decorative Ceiling Fans are high speed fans, which are available with four blades to provide maximum air delivery and best for all small rooms. Non-Decorative Ceiling Fans has variety of designs and colors available at the best competitive prices. Non-Decorative Ceiling Fans consists of power saving technologies which make it more unique and high monopoly holder in the competitive market.

Wall Mount Fans are available in sleek and stylish look with less noise and delivers maximum air pressure. Wall Mount Fans are integrated with aluminium blade coated which increases its life and also gives an elegant look to your room. Wall Mount Fans are available in many colors like Blue, Red, Brown, Cherry and lots more.

Decorative Ceiling Fans are one of the most demanding ranges of fans in the market. The aluminium body with golden touch offers a unique look and suits any decor. These days, the latest technology of power saving in fans attracts the market and consumers as well.

Industrial Fans Manufacturer & Supplier

Canada Fan sales offices are located throughout North America and manufactured around the world. Wherever you are, “We want you to enjoy doing business with us.” Leave it to Buffalo Fan to take a perfectly reliable fan and offer a quieter, more efficient, less costly alternative. Canada Fan Corporation is committed to offering a wide variety of fans to meet your needs. Please visit our link, below, to view our capabilites and vast selection of designs.

To meet these operating conditions, Canada Fan / Canada heavy duty fans are designed and selected with the use of modern computer techniques guided by over 100 years of fan engineering experience. Comprehensive testing confirms design decisions. Quality manufacturing standards guarantee long service life.

Industrial Fans & Blowers Excellence

Over the years, Canada Fan / Canada supplied fans, blowers and pumps to a wide range of industries and applications. When prolonged service wears fan wheel the logical replacement is a new fan wheel built to the original design. A technical support and sales agent will get a replacement wheel, shaft, bearings, accessories, etc. in the shortest time. She, or he may also recommend changes to extend service life and performance of your machinery, including special materials of construction, explosion-proof and spark-resistant design, variety of coatings and accessories, intended to meet practically any application needs.

Ventilator Fans – Methods of Building Ventilation

When straightforward breeze conditioning system is possible, the rate of air velocity method outlined above should be the basic method used. However, there may be rooms or areas within the building that will require special treatment. If so, one of the other methods, such as spot cooling or zone cooling, may be combined with the basic method to achieve the over-all objectives.

Air circulators

Air circulators may be effectively used to boost air velocity through large buildings that have a flow pattern difficult to control. Air circulators are also used to redirect air into occupied areas near floor level. Air circulators are also effectively used in locations where adequate exhaust and supply air fans may be lacking. Air circulation alone may provide heat relief and cooling comfort to individuals in the area. Northern Fan’s Type CABL fan is ideally suited to this application. For many installations, fans like this may be positioned 8′ to 10′ above the floor and at approximately 50′ intervals to obtain a continuously circulating column of air across a room or building. To broaden the column of air, fans should be located abreast of each other 15′ to 20′ apart. Fan locations and positions are easily adjusted to the requirements of the area.

Although an accurate, intelligent calculation of the required air volume for a breeze conditioning system has been made, there are practical limitations in most buildings that may seriously affect the final results. By giving these limitations proper consideration in the planning stage, the system can usually be modified to compensate for them. Some of the more common limitations are listed here.

Air Flow Restrictions due to interior partitions

It is obvious that interior partitions restrict and interrupt the flow of air through a structure. The effect of these partitions on the system must be analyzed and solutions found. In buildings with very high ceilings. the cross-sectional area factor may become unrealistic in calculating the required air volume. In most instances, inexpensive baffles can be installed across the building width to reduce the effective cross-section to an area 10′ or 12′ above floor level. Machinery, raw materials and finished goods that obstruct air circulation. These obstacles, like interior partitions, must be considered and methods worked out to overcome the problems they create to the proper circulation of air through the structure. Frequently, the location of heat-producing machinery will seriously interfere with the preferred pattern of air circulation. This situation can destroy the effectiveness of the system. An alternative plan to overcome the problem is essential.

Another limitation of the very high ceiling or roof is the difficulty of maintaining the air velocity near floor level. The baffle method just described is usually the best way to reconcentrate the air flow along the floor level where it will be effective in providing personnel comfort. In large buildings, baffles may be required at l00-foot intervals to keep air flow near the floor level.

Operations within the area frequently require wall openings or loading doors that will drastically interfere with the desired airflow pattern. In some cases, individuals may open windows that should remain closed to maintain effective air circulation. A remedy for each of these problems is required. For maximum efficiency and economy, a good layout will avoid the restricted intake opening. The type of exhaust equipment normally utilized is most economical and efficient if static pressure in the system is 1/8″ or less. To obtain this condition, air velocity through intake openings should not exceed 1,000 feet per minute, a lower figure is usually desirable.

Additional information can be found at the Northern Fan web site http://northernindustrialsupplycompany.com/products/ilg.html

Blower Fan Ventilator – Air Make Up Fans

Lack of make-up air in a building can cause serious problems. Many times the problems are not even recognized and show themselves in ways that most people do not think about. A properly designed and installed ventilation system provides environmental control by avoiding negative pressure. Uncontrolled infiltration of air through window sashes, doors and walls leads to many undesired results. In this article we will discuss a few of these problems and inform you about the cost of make-up air.

The signs that You need Make-up Air Fans include:

1) Poor paint finishing due to dust, moisture or fumes. Exhaust fans will compete with each other for the available air. They are going to pull air from anywhere they can. Paint booth fans may lose out in the competition causing the paint to retain moisture and collect dust that is not removed by the exhaust fans.

2) Walls have moisture being pulled through. This shows that your plant is under negative pressure. Cement walls have small cracks that allow water to penetrate. Fans pull from every place air can get through. This includes walls. When fans pull air through walls, water from rain and other outdoor sources will also be pulled through. This will cause firring strips to rot, ruin wall coverings and paint jobs.

3) Smoke, haze and dust floating in the air. As you look across the factory is it hazy? You should be able to see clearly from one end of your factory to the other without the view being blocked by haze and smoke. If the area clears when a window or door is opened, it is starved for air. This indicates that the exhaust fans are competing for air. Welding, molding, metal cutting or many other processes can generate fumes that need to be exhausted or the factory could become hazy.

4) Stacks and exhaust fans take up a large portion of your roof. If this is the case, you are a prime candidate for make-up air. The number of stacks and exhaust fans on the roof is an easy way to gauge the amount of makeup air needed. The area of inlet air should be equal to or greater than the area of exhaust air. The hoods seem to have a downdraft rather than the normal updraft. The fumes from hoods are supposed to go up the hoods, but if the fan is starved for air the fumes will be found in the plant. This is also true for gas hot water heaters, boilers, furnaces and unit heaters or any other process that has a flue on it.

5) Fan motors also work harder when they are required. When a fan attempts to move air that is not there, it causes the load to rise. This causes the insulation to break down and shorten life. Motors should last 7 or more years. When every exhaust fan in the plant is fighting for the same air, all the motors are going to have decreased life.

6) When walking through the plant, odors seem to linger. Weld fumes, paint fumes and dip tanks all need to be exhausted. These fumes can cause undesirable mixtures of odors that linger and cause burning, watery eyes, sore throats or sinus trouble. This contributes to an Locker room, bathroom and other odors seem to creep through the plant and office. People’s clothes smell like the production line. Processes like oil mist, boilers, roasting ovens and paint booths have odors. All these aromas require ventilation. If the ventilators cannot provide the required number of air changes in the room, your plant is short of air.

7) Doors that are hard to open or doors that will not shut on their own are a sure sign that the plant is short of air. Inward swinging doors are easy to open and hard to close. Drafts through the door seals and knobs that are hard to turn add to the problem. Outward swinging doors are hard to open and “slam” shut, damaging seals and wearing hinges. Hydraulic door closer settings are set high to pull doors closed without slamming.

8) Shutters on the exhaust fans are not 100% open. Automatic or balanced shutters are not open. These shutters should be 100% open when the exhaust fans are running. If the exhaust fan is not getting enough air, the shutter will not open all the way. The shutters should gradually close when the fan is turned off. They should not slam shut.

9) Steel near the fume hoods is corroding due to fumes that should be exhausted. Many corrosive liquids require their own hood. Typically the hood is a stainless steel and will not deteriorate from the fumes. If the air is not going up the hood and fumes are being pulled through another exhaust fan that is not designed to handle the corrosive atmosphere, the fan and any nearby steel will also corrode and decrease the life of the unprotected equipment.

10) Cracks under the doors collect leaves, dirt or gum wrappers. The threshold of the door will collect a substantial amount of debris during the day due to the exhaust fans trying to grab air from anywhere they can get it. Part of grabbing the air will be the collection dirt and trash.

11) Cold walls. The walls should not be cold. The wall can act as an insulator if the air is balanced. Insulation will prevent some drafts, but no insulation will prevent all the air from coming through. With negative pressure, however, the drafts through the wall will be cold regardless of the amount of insulation. These cold drafts will cause absenteeism and help spread colds and illness throughout the building. People will constantly fight over the thermostat setting. Fuel will be conserved with proper ventilation. Without make-up air, cold conditions near the building perimeter and overheated areas in the middle of the building lead to installation of more inefficient unit heaters. These heaters work overtime to heat the air, which in turn gets pulled to center of the building thus adding to the overheating problem.

12) Pilot lights go out and the area smells of flue gases. The flue gases from the unit heaters must go up. When makeup air is needed, these gases do not go up the flue but back into the building. Unit heaters are not necessary with the proper makeup air units. The heat for the plant will come from the makeup air unit and the unit heaters will not run.

Industrial Building Ventilation

Based on the objectives and funds available, one can now consider different alternatives for industrial building ventilation and select the best method to use in calculating air volume requirements. A description of these methods follows. This is a time-honored approach to a determination of air volume requirements. It is based on the theory that a complete change of air in a room or building should be made at a certain time frequency. The rate selected is frequently an arbitrary decision. It may be based on experience with similar installations or may be established by a health or safety code. Many fan manufacturers have published charts that show recommended rates of air change for typical installations. Although the rate of air change method of calculating air volume has been used for many years, Buffalo Fan engineers have found it unsatisfactory except in relatively small buildings or rooms. For jobs that involve personnel comfort. this method is not recommended if the building is over 50,000 cubic feet in content or more than l00′ in length.

Considerations for Building Ventilation

The volume of air required to operate a ventilating and cooling system is a very fundamental requirement. Before air volume is estimated or calculated, careful consideration should be given to the following factors. Be sure that the decision you make will accomplish the most important objectives or will overcome the most important problems. This should be the overriding consideration in the selection of a system of ventilation. Availability of money to finance the system is a factor that must be considered early in the planning stage. The funds available will affect the objectives you set and will influence the system of ventilation selected to meet the objectives.

CFM per square foot of floor area method

CFM per square foot of floor area method: this method of calculation is a modern adaptation of the rate of air change formula. Total air volume (cubic feet per minute) is determined by multiplying the total square feet of floor area by an arbitrary CFM per square foot figure. The figure selected may be as low as 2 CFM or as high as 12 CFM per square foot. Four CFM per square foot has been recommended as a minimum for summer ventilation of large assembly type operations. This method of calculation, like the rate of air change method, is likely to produce unsatisfactory results in many cases. Failure to control air distribution and air velocity can be a major weakness in the whole concept. Selection of a CFM per square foot figure should be based on experience and a proven method of air distribution.

Rate of air velocity method

Rate of air velocity method: This method of calculating air volume needed for a system is highly recommended by American Coolair. A breeze conditioning system can be highly effective in providing personnel comfort in hot weather if the recommendations outlined below are observed. It has been determined from field experience that an average air velocity of 150 feet per minute (FPM) to 200 FPM is usually sufficient for personnel cooling under summertime conditions. The CFM required to do the job is calculated by multiplying the cross section of an area through which the air is to move by the desired velocity. This is expressed in the following formula.

Factors Affecting Average Air Velocity

As building size increases, there are factors that will affect the average air velocity through the cross section of the building. The longer the building, the greater the amount of air leakage from windows, doors, elevator shafts, etc. To offset this air leakage, air velocity should be increased. This is done by relating the calculated velocity to the length of the building. The results will provide an effective velocity of approximately 150 ft./min.

Industrial Ventilators

In some buildings. it is not possible or practical to install a complete ventilation system. In such situations, zone cooling may be effectively used. The problem is similar to a spot cooling application, but usually involves a relatively larger area. Effective zone cooling may be accomplished by use of air circulators. See Air circulation below. A very satisfactory zone cooling method is the use of supply-type PRVs to flood the problem area with fresh, cooler air. The adjacent drawing and zone cooling table illustrate the capacity of several American Coolair PRV models to effectively cool an area. The figures are based on discharge of air approximately l5 feet above floor level.

Additional information can be found at the Canada Blower company web site http://canadablower.com/ahu/index.html

Ventilation with Ventilators and Blower Fans

Canada Fans Co. provides fans for every type of commercial structure including airports, arenas, stadiums, distribution centers, malls, offices, and retail. Canada Fans also offer smoke and heat exhaust fans that are UL listed for Smoke Control Systems and a full line of kitchen fans that are UL 762 listed for the exhaust of grease-laden air. Canada Fans engineers design, test, and manufacture fans for all types of buildings, including condos, custom homes, offices, malls, airports, arenas, and stadiums. We are able to meet your most precise requirements for a variety of HVAC equipment, including all types of custom, package air handlers and roof top units. In addition, Canada Fans can provide exhaust for restrooms, elevator shafts, parking garages, and jet bridges; stairwell pressurization; rooftop and sidewall supply and exhaust, including smoke and heat exhaust fans that are UL listed for Smoke Control Systems, as well as kitchen fans that are UL 762 listed for the exhaust of grease-laden air.

Exhaust Fans, Roof Ventilators

Canada Fans supplies thousands of fans to universities, hospitals, laboratories and research facilities, military bases, hotels, convention centers, and cruise ships around the world; working closely with architects, engineers and contractors to design and test fans that can meet the most precise quality and reliability requirements. Canada Fans makes smoke and heat exhaust fans that are UL listed for Smoke Control Systems, kitchen fans that are UL 762 listed for the exhaust of grease-laden air, and a full line of laboratory and fume exhaust systems. Canada Fans provides fans for numerous residential building applications, such as stairwell and elevator shaft pressurization; kitchen, restroom, and pool exhaust; and every aspect of HVAC, including air handlers, gravity ventilators, and large rooftop units.

Industrial Blower Fans

Manufacturing facilities require a large amount of ventilation to maintain a healthy work environment for the people working within the buildings. Canada Fans designs and builds fans to control and handle the exhaust, supply, and make-up air requirements for all types of manufacturing environments and spaces. The exhaust of welding and other noxious fumes and dusts, as well as the exhaust of hot air produced from ovens and other high temperature processes, are essential to providing safe and comfortable working conditions. In many cases, the building heating, cooling, and air conditioning (HVAC) requirements are also critical for proper production control and working conditions. A wide variety of businesses, industries, medical facilities, and institutions require ultra clean environments for research and development as well as production of specialty products and equipment. These facilities demand high filtration and positive pressures inside the clean room space to control the process and limit potential contamination. Other requirements typically include variable air volume, high efficient air moving equipment, low noise, and ultra-low vibration levels from the mechanical equipment.

Energy Efficient Blower Fan Ventilators

Among many other changes, the green revolution has created a greater need for more energy efficient fans and ventilation equipment. As a leader in the fan industry, Canada Fans engineers and manufactures high efficient products for a wide variety of green friendly applications including LEED building designs, biofuel and biomass production plants, landfills, solar film manufacturing facilities, as well as numerous waste energy and heat recovery systems. Regardless of how unique or specialized your process is, Buffalo Blower can customize our products to meet virtually any requirement.

Axial Ventilators and Fans

Canada Fans is well known for leveraging its design and manufacturing capabilities when constructing the heavy duty fans required for marine applications. Such marine duty fans are used for many purposes including boiler combustion air, mechanical ventilation, off shore rig diesel generator exhaust disbursement, pressurization, engine cooling, and dust control. Our air moving equipment can be found on drilling rigs, production platforms, tug boats, cruise ships, ferries, and cargo ships. We offer a number of features to meet the specific needs of the marine industry. These include shortened axial fan housings for operating in tight spaces, cast aluminum impellers and hot dip galvanized steel components for extended durability, spark resistant construction for potentially explosive air streams, water tight electrical connections to withstand corrosive environments, and IEEE 45 marine duty motors for both above deck and below deck installations.

Other Blower Fan Types

In addition to our extensive fan design and manufacturing experience, Canada Fans offer a number of products meeting requirements of the marine industry’s governing and standard organizations including: